I think this song is about the fact that when it comes to arguments or differing points of view, you think you're right and also know that the other person believes in their truth just as much. It's hard to make (not just romantic but every kind of) relationships work when two people are very different, so he's contemplating whether they should try and force their opinion on one another until someone gives in, or just agree to disagree and hope their differences won't matter in the long run. He's worried the other person is not so forgiving and indifferent about it, and all these disagreements will drive them away from him, but he can't change overnight (and doesn't think he should anyways).
I think this song is about the fact that when it comes to arguments or differing points of view, you think you're right and also know that the other person believes in their truth just as much. It's hard to make (not just romantic but every kind of) relationships work when two people are very different, so he's contemplating whether they should try and force their opinion on one another until someone gives in, or just agree to disagree and hope their differences won't matter in the long run. He's worried the other person is not so forgiving and indifferent about it, and all these disagreements will drive them away from him, but he can't change overnight (and doesn't think he should anyways).